According to a new iSuppli Corp study, more than half of all cars sold in the United States during 2009 will offer some type of iPod connectivity. In 2008, 39 percent of models already sport this feature, but that number is expected to jump to 58 percent next year, which will mark the first time that more than half of cars will have this capability.

The jump in iPod-related options occurs as U.S. consumers increasingly demand improved connectivity between their vehicles' audio/video systems and their Portable Media Players (PMPs), the article said. The iPod, meanwhile, represents at least 70 percent of the overall U.S. market in sales—depending on the particular day and the particular report you're reading, it can climb as high as 80 percent.

Bluetooth has seen even greater adoption; the same study said that 82 percent of all models available in the U.S. in 2009 will either have it standard or offer it as an option. Newer implementations of Bluetooth include voice recognition and streaming media transfers to the car's stereo system, according to the article. Hard drives and location-based services are further down the popularity scale. No number was given for navigation, but hard drives look to be available either as standard equipment or as an option on about one-third of all models in 2009.